HB2025 - the 71st ICFA Advanced Beam Dynamics workshop on High-Intensity and High-Brightness Hadron Beams

Beam dynamics studies on the ISIS RCS with a new assessment of non-linear driving terms and motion

WEIDB01

Oct 22, 2025, 4:30 PM

30m

room B (conference center)

Invited Oral Presentation WGA:Beam Dynamics in Rings WEIDB WGA invited oral

Speaker

ESMAEIL AHMADI (Science and Technology Facilities Council)

Description

ISIS is the pulsed muon and neutron source at RAL in the UK. Its operation centres on an 800 MeV rapid cycling synchrotron (RCS) running at 50 Hz, delivering 3×10¹³ protons per pulse and 0.2 MW average beam power to neutron targets.

Current studies are aiming to improve the measurement, modelling, and control of ISIS ring beam dynamics, with the goal of optimizing operational setup and benchmarking beam loss studies for ISIS and the proposed MW upgrade, ISIS-II. This paper gives a brief overview of linear and non-linear longitudinal and transverse beam dynamics studies at ISIS, as well as beam measurement and modelling. The paper then focuses on non-linear beam dynamics studies in the low-intensity regime.

Measured beam loss maps in tune space have been used to identify non-linear resonance lines. To better characterize individual resonance lines and improve the non-linear lattice model, comparisons are made between loss maps from experiment and results from extended particle tracking, Frequency Map Analysis (FMA) simulations, and analytical calculations. Detailed investigations of the third-order resonance lines 3Qx=13 and Qx+2Qy=12 are outlined.